1. Field
The embodiments disclosed herein relate generally to 3-D image generation and the identification of objects, tracking of objects, road hazard avoidance, and collision avoidance in short range automotive applications and more particularly to a ladar sensor assembly having a laser transmitter, laser sensor and digital processor integrated in an envelope inserted into a vehicle body panel.
2. References to Related Art
The 3-D imaging technology disclosed in Stettner et al, U.S. Pat. Nos. 5,446,529, 6,133,989 and 6,414,746 provides with a single pulse of light, typically pulsed laser light, all the information of a conventional 2-D picture along with the third dimensional coordinates; it furnishes the 3-D coordinates of everything in its field of view. This use is typically referred to as flash 3-D imaging in analogy with ordinary digital 2-D cameras using flash attachments for a self contained source of light. As with ordinary 2-D digital cameras, the light is focused by a lens on the focal plane of the LADAR sensor, which contains an array of pixels called a focal plane array (FPA). In the case of a LADAR sensor these pixels are “smart” and can collect data which enables a processor to calculate the round-trip time of flight of the laser pulse to reflective features on the object of interest. Each smart pixel also collects data associated with the returning laser pulse shape and magnitude. One value of these flash LADAR sensors, as opposed to competing designs in which one or more pixels is scanned over the field of view, is the elimination of the precision mechanical scanner, which is costly, high maintenance and typically large and heavy. The pixels in the focal plane of a flash LADAR sensor are automatically registered due to their permanent positions within the array. Further, by capturing a frame of data as opposed to one or a few pixels with one laser pulse, the data rate is greatly increased while weight and volume are reduced. Because each frame of data is captured from the reflection of a short duration laser pulse, moving objects or surfaces of stationary objects may be captured from a moving platform without blurring or distortion.
The driver and passengers of an automobile are exposed to dangers from other vehicles and a number of road hazards. In avoiding side impacts, grazing contact, or low speed impacts in the driver blind spots a sensor is needed which can be installed in multiple locations on a vehicle at low cost.
Many systems have been proposed to meet the challenge of using optical imaging and video cameras in a vehicle system to create 3-D maps of scenes and models of solid objects, and to use the 3-D database to navigate, steer, and avoid collisions with stationary or moving objects. Stereo systems, holographic capture systems, and those which acquire shape from motion, have all been proposed and in some cases demonstrated, but what is lacking is a system with the capability of rapidly capturing 3-D images of objects and roadway features in the path of a moving vehicle, or travelling on an intersecting path, and which controls and adapts the host vehicle so as to avoid collisions and road hazards, and steer the best path.
It is therefore desirable to provide, a low cost side and/or rear short range, or proximity sensor to enable such a collision avoidance system with full 360 degree capability.